dt-bindings: arm: remove optional properties for SCMI Regulators

Remove optional properties bindings descriptions for SCMI Regulators.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20201123202336.46701-2-cristian.marussi@arm.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/arm/arm,scmi.txt

@@ -71,20 +71,11 @@ It does not support any current operation.
 SCMI Regulators are grouped under a 'regulators' node which in turn is a child
 of the SCMI Voltage protocol node inside the desired SCMI instance node.
 
-This binding uses the common regulator binding[6] but, due to SCMI abstractions,
-supports only a subset of its properties as specified below amongst Optional
-properties.
+This binding uses the common regulator binding[6].
 
 Required properties:
  - reg : shall identify an existent SCMI Voltage Domain.
 
-Optional properties:
- - regulator-name
- - regulator-min-microvolt / regulator-max-microvolt
- - regulator-always-on / regulator-boot-on
- - regulator-max-step-microvolt
- - regulator-coupled-with / regulator-coupled-max-spread
-
 Sensor bindings for the sensors based on SCMI Message Protocol
 --------------------------------------------------------------
 SCMI provides an API to access the various sensors on the SoC.